Grey's Anatomy to Welcome Tim Daly
03/07/2007 AT 08:45 AM EST
Daly, 51, will appear on a special two-hour episode of the ABC drama that could serve as a springboard for a spinoff series, according to The Hollywood Reporter.
The spinoff would star Kate Walsh, who plays Dr. Addison Montgomery-Shepherd on Grey's Anatomy, ABC reps confirmed to PEOPLE in February. Actor Taye Diggs has also signed on to appear in the expanded episode.
According to The Hollywood Reporter, Daly's character is described in a production breakdown as "handsome, sincere, like a McDreamy."
Paul Adelstein, who plays double-crossing Secret Service agent Paul Kellerman on FOX's Prison Break, has also been cast, although it's unclear what role he will play.
Grey's creator Shonda Rhimes is writing the special episode, details of which are being kept under wraps but which USA Today reports will feature Walsh's character mulling an out-of-town job offer. Should the spinoff go forward, Addison will most likely accept the offer.
Daly most recently starred in ABC's critically lauded drama The Nine.